The present application is related to automotive service lifts onto which a vehicle is driven in order to be elevated during a vehicle service procedure, such as a wheel alignment service, and in particular, to a vehicle position detection and guidance system configured to guide a vehicle moving onto the supporting runway surfaces of the automotive service lift, as well as to detect potential obstructions present in the path of either the vehicle or vertical movement of the lift itself.
Numerous vehicle service procedures require or benefit from elevating a vehicle undergoing a service to a convenient working height for a service technician. As such, it is common practice for the service technician to initially drive the vehicle onto an automotive service lift located within a service bay or vehicle inspection area. A typical automotive service lift consists of two parallel runways, onto which the wheels of the vehicle are driven. An approach end of the automotive service lift may include a set of inclined ramps over which the vehicle drives as it moves onto the runways, while the opposite end of the automotive service lift may include a set of stops or end plates to prevent the vehicle from being accidentally driven or rolled off the end of the runways. If the lift is installed in a floor recess, such that the runway surfaces are level with the surrounding floor in a lowered configuration, no approach ramps are required. Depending upon the particular configuration of the automotive service lift, movable surfaces such as turn plates and slip plates may be located on the runways between the approach end and the stops, such as shown in U.S. Pat. No. 7,308,971 to Liebetreu et al., which is herein incorporated by reference.
Driving a vehicle onto an automotive service lift requires that the vehicle be initially positioned with the wheels in-line with the lift runway surfaces, and that the approach path be maintained in a straight direction parallel to the service lift centerline as the vehicle moves onto the runways. Excessive steering of the vehicle, or initial misaligned of the wheels and runways can potentially result in the vehicle being driven off an edge of the runways. As the vehicle moves onto the lift runways, the driver's view of the runway surfaces is commonly obscured by the front of the vehicle, rendering it difficult to apply steering corrections or determine where to stop the vehicle. Failure to stop the vehicle at an appropriate location on the runways surfaces can either leave rear wheels of the vehicle off of the service lift, or can cause the front wheels to abut against the stops or end plates. For some vehicle service procedures, it is required that the vehicle be stopped at specific locations on the runways, and subsequently rolled either forward, backwards, or in both directions over a short distance. During the subsequent rolling, vehicle measurements are acquired, the suspension relaxed, and/or the vehicle positioned on a set of the movable surfaces.
Proper driving and positioning of the vehicle onto the lift runways either requires a second technician to provide guidance to the vehicle driver, or the use of a mirror or other visual guide located within the driver's field of view. Over time, a skilled technician is likely to develop an intuitive sense of where the vehicle front wheels are located, and approximately where to stop the vehicle, but due to differences in vehicle wheelbase dimensions, it remains difficult to determine where the rear wheels are relative to the runway surfaces or how close the wheels may be to an edge of the runway surfaces.
Absent a second technician observing the location of all four vehicle wheels and the lift runway surfaces, it is challenging for a service technician in the vehicle driver's seat to be fully aware of the vehicle wheel positions and any potential obstructions which may have been left on the lift runway surfaces during a prior service procedure. Mirrors and monitors, while useful, in maintaining the vehicle direction of travel, and providing a visual indication of where to stop the vehicle, generally do not enable adequate viewing of the lift runway surfaces under the vehicle, and therefore fail to provide a driver with any indication or warning of potential obstructions on the lift runway surfaces, such as wheel chocks or misplaced tools.
Accordingly, it would be beneficial to provide an automotive service lift with a vehicle position detection and guidance system capable of accurately monitoring the position of a vehicle approaching, departing, and/or disposed on the lift runways, so as to provide a service technician with any necessary steering and stopping guidance while positioning a vehicle on or off the service lift during a service or inspection procedure.
It would be further beneficial for the vehicle position detection and guidance system to observe not only the position of the vehicle wheels relative to the lift runway surfaces, but also to detect the presence of any obstructions to vehicle movement located on the lift runway surfaces, such as wheel stops, tools, jacks, or other items inadvertently left behind during a previous vehicle service or inspection procedure. Similarly, it would be beneficial for the vehicle position detection and guidance system to observe the spatial volume beneath both the vehicle and the automotive service lift (when elevated), to ensure that no obstacles are present which would interfere with either vehicle movement or changes in the lift elevation.